Jazz, As has been stated the idea would be to keep it simple, very rigid and straight forward to build. I am aware that cutting ally would up the anti, but it also vastly increases the scope of the machine, and would be useful for a "future" Monster build.

How does vertical work? material hold, retaining cutout components etc., would it really save any space? - I suspect not. best keep it simple, which probably
means conventional, although its good to think outside the box.

IMHO the best choice for the frame would be hot-rolled section, either steel or ally (both of which can be of welded or bolted construction, although ally welding requires more skill). How does a braced channel section compare with box or RHS for strength and rigidity?, this may be easier to make stronger bolted connections - just thinking out loud.

Yes it is difficult at this level, but that is probably why most available kits etc. don't quite cut the mustard. Also the idea behind this suggested project.

This machine is intended to be an improvement on anything currently available so I don't think MDF comes into the equation. I am sure some people have achieved some success with MDF, but do not feel that it is suitable for this particular project.G